Burner for diesel particulate filter regeneration

ABSTRACT

Provided is a burner using electric discharge as an ignition source such as arc or plasma rotating with flow, and more particularly, to a DPF regenerating burner that improves ignition performance of the burner by having a metal ball on a conical electrode surface where electricity is discharged, inducing accurate electric discharge through a metal ball, and supplying a fuel-air mixture toward the metal ball. The DPF regeneration burner includes a fuel-air mixture supplying unit having an injecting unit be connected to a reaction unit to supply the fuel-air mixture to the reaction unit; and a metal ball on a circumference of the electrode to ignite the injected fuel-air mixture. The DPF regenerating burner generates electric discharge in an electrode surface where a metal ball is located. The ignition performance is improved by accurately supplying a fuel-air mixture at a location where the electric discharge is generated.

TECHNICAL FIELD

The present invention relates to a burner using electric discharge as an ignition source such as arc or plasma rotating along with flow, and more particularly, to a burner for regenerating diesel particulate filter (DPF) which can trap hazardous particulates, i.e., sooty smoke and which further can improve ignition performance of the burner by having a metal ball on a conical electrode surface where electricity is discharged and supplying a fuel-air mixture toward the metal ball.

BACKGROUND ART

Since a diesel vehicle has a better fuel-efficiency and greater power than a gasoline vehicle, the diesel vehicle is applied a lot as heavy duty vehicles. However, in the diesel engine, differently from a gasoline engine, emits the particulate emissions because fuel is injected into the engine combustion chamber directly during compression stroke and it is burns incompletely due to insufficient mixing of fuel and air in the above process.

According to a report, the exhaust gas is formed of hazardous particles of small sizes, which are harmful to a human body, and hazardous particles by the diesel vehicle take 40% of total air pollution. Accordingly, many countries regulate diesel particulate emissions and a Diesel particulate filter for reducing particulate emissions has been commonly used.

However, the typical Diesel particulate filter adopts a passive regeneration method in which the trapped particulates in a catalyst coated filter and oxidized by the catalyst. However, when there are a lot of slow driving loads, for example of terrible traffic congestion, the temperatures of the exhaust gas are too low to regenerate the filter passively. When the filter is not regenerated properly, power is reduced and fuel consumption rate increases due to increased exhaust back pressure. When such a status continues, an engine as well as the filter will be damaged.

A complex method that combines the passive regeneration method by the catalyst with an active regeneration method using an electric heater, a burner, and throttling is suggested in order to solve the above problem. For example, KR Patent Publication No. 2004-68792 discloses a diesel exhaust gas aftertreatment device using electric heater. There is a benefit in using the diesel exhaust gas aftertreatment device since it activates the reaction of a catalyst by the electric heater to thereby help passive regeneration. However, since a large capacity of battery is required in order to raise the temperature of the exhaust gas, it is practically difficult to apply the diesel exhaust gas aftertreatment device.

In order to solve the problem, KR Patent No. 10-0699495 discloses a plasma reactor for a DPF system, and a PM reduction device using the same and it is shown in FIG. 1.

As shown in FIG. 1, the burner for the DPF system and the PM reduction device using the same include an engine 20, an exhaust pipe 40, which is connected to a Diesel particulate filter 10 for oxidizing and removing particulate matters (PM) generated from the engine 20 through an oxidation catalyst 10′, a burner 50 for activating reaction of a catalyst by plasma reaction of an electrode by injecting liquid fuel to an outer side of the exhaust pipe 40, and a fuel storage tank 30 for supplying fuel to the burner 50 and an engine 20.

The burner shown in FIG. 1 has a benefit that the performance of the Diesel particulate filter is improved by burning and warming Diesel particulate. However, since the burner is installed vertically to the exhaust pipe, non-uniformity of temperature distribution inside the exhaust pipe is caused as a temperature of a region close to the burner is high but a temperature of a region far from the burner falls down.

According to the above problem, regeneration load is centralized to a specific portion of an oxidization filter, which is the Diesel particulate filter thereby cause reduction of a life-span of filter. In order to achieve uniformity of the temperature distribution, an additional mixing chamber is required.

In addition, since the burner is formed on an outer side of the exhaust pipe, a space for forming the burner is additionally required and there is a strong possibility that an error occurs due to external shocks.

DISCLOSURE Technical Problem

An embodiment of the present invention is directed to provide a burner which can improve filtering performance and extend a life span of a Diesel particulate filter by uniformly forming temperature distribution in an entire region of an exhaust pipe by providing the burner as a portion of the exhaust pipe and forming flame by an electrode to be in parallel with a direction of the exhaust gas, and a particulate matters (PM) reduction device having the same. Also, since an additional space for providing the burner is not required, special efficiency and durability are improved to reduce occurring of errors due to external shocks.

Another embodiment of the present invention is directed to provide a burner for regenerating a diesel particulate filter (DPF) which can accurately control a location of starting electric discharge by having a metal ball on an electrode of the burner, accurately providing a fuel-air mixture to an electric discharging unit, and providing fuel which is efficiently vaporized through exhaust heat and an additionally installed electric heater before igniting the mixture.

Technical Solution

To achieve the object of the present invention, the present invention provides a burner for regenerating diesel particulate filter (DPF) which generates rotating electric discharge such as plasma or arc by applying high voltage to a reaction unit where there is rotation flow of fuel and air and generates ignition, includes: an outer casing 110 which has a hollow inside to be a portion of an exhaust pipe for connecting a Diesel particulate filter for filtering particulate matters (PM) generated from an engine, and which includes a fixing unit 111 to be coupled with the exhaust pipe in both sides; a body 120 which is formed inside the outer casing 110 and includes a reaction unit 121; an electrode supporting unit 122 which is formed inside the body 120; an electrode 130 whose one side is fixed to the electrode supporting unit 122 and which is installed on the reaction unit 121 of the body 120; a conducting bar 125 for supplying power to the electrode 130; a supplying unit for supplying fuel and air from the fuel supplying unit 141 and the air supplying unit 140 to the reaction unit 121; and an injecting unit 146 which is formed to be connected to the supplying unit and injects fuel and air to the reaction unit 121.

The supplying unit may include a fuel-air mixture supplying unit 142 for supplying a fuel-air mixture to the reaction unit 121 by being connected to the air supplying unit 140 and the fuel supplying unit 141, and the injecting unit 146 injects the supplied fuel-air mixture to the reaction unit 121; and

a metal ball 150 is included on a circumference of the electrode 130 to ignite the injected fuel-air mixture.

The fuel-air mixture supplying unit 142 may include a rotational passage 143 between an inner wall and an outer wall of the body 120 along with a circumferential direction of the body 120; and the injecting unit 146 injects the fuel-air mixture passing through the rotational passage 143 into the body 120.

A cross-sectional area of the electrode 130 may decrease gradually along with the moving direction of the exhaust gas.

The burner, further includes: a secondary air supplying unit 160 which is connected to an outer side of the body 120 and which has an outlet end 162 be connected to the reaction unit 121 in order to supply air to the reaction unit 121,

wherein the secondary air supplying unit 160 includes the outlet end 162, which is formed to be inclining at a selected angle with respect to the electrode 130, such that air supplied through the secondary air supplying unit 160 flows in a moving direction of the exhaust gas by swirling along with a circumference of the electrode 130.

The supplying unit is formed on a center of the electrode supporting unit 122 and includes the fuel passage 123 connected to the fuel supplying unit and an air passage connected to the air supplying unit which covers a surface of the fuel passage 123, such that the fuel and the air are mixed in end units of the fuel passage and the air passage and are supplied to the reaction unit 121; and

since a plurality of nozzles 131 are formed on an upper portion of the electrode 130, the mixed fuel and air moves outside the reaction unit 121 along with the nozzle 131.

The nozzle 131 may be formed to be inclining at a selected angle with respect to a tangential direction of the electrode 130 such that the mixed fuel and air swirls.

The secondary air supplying unit 160 including a secondary air passage 161, which includes the outlet end 162 connected to the reaction unit 121 such that auxiliary air flows outside the electrode 130 of the reaction unit 121, supplies air to the secondary air passage 161,

wherein the secondary air supplying unit 160 is formed to be inclining at a selected angle with respect to a longitudinal direction of the body 120 such that air supplied by the secondary air supplying unit 160 swirls.

The burner 100 may include an electric heater 170 installed on the supplying unit,

wherein the electric heater 170 is controlled by a Pulse Width Modulation (PWM) control method.

The body 120 may include a magnifying pipe 180 on a rear end,

wherein the magnifying pipe 180 includes a through hole 181 and the magnifying pipe 180 is located in a front position of the end of the electrode 130 in an inflow direction of the exhaust gas.

Hereinafter, the embodiments of the present invention will be described in detail with reference to accompanying drawings.

FIG. 2 is a schematic view showing a diesel particulate reduction device at which a burner of the present invention is installed. FIG. 3 is a perspective view showing a burner in accordance with an embodiment of the present invention. FIGS. 4 and 5 are cross-sectional views taken along the lines AA′ and BB′ in FIG. 3. FIG. 6 is a view showing an operation state of FIG. 4. FIG. 7 is a front view showing an expansion pipe in accordance with an embodiment of the present invention.

The diesel particulate reduction device having a burner 100 of the present invention will be described with reference to FIG. 2. The diesel particulate reduction device includes the burner 100, which is installed on an exhaust pipe through which exhaust gas generated from an engine 200 moves and heat the exhaust gas, and a Diesel particulate filter 400, which is installed on a rear end of the burner 100 and has an oxidation catalyst 410 on a front end to filter particulate matters of exhaust gas.

As shown, the burner 100 forms a specific portion of an exhaust pipe connecting the engine and a Diesel particulate filter, and exhaust gas generated from the engine moves through an exhaust pipe connected to the engine, the burner 100, and an exhaust pipe connected to the Diesel particulate filter, to thereby efficiently warm up the exhaust gas generated from the engine.

The burner 100 shown in FIGS. 3 to 5 is a format of the burner 100 but may have diverse formats. The burner 100 will be described in detail with reference to drawings below.

The embodiment of the present invention will be described in detail with reference to drawings.

Referring to FIGS. 3 to 6, the burner 100 of the present invention includes an outer casing 110 for forming a part of the exhaust pipe, a body 120 for forming a reaction unit having flame inside, an electrode 130 which is included inside the body 120, a fuel-air mixture supplying unit 142 for supplying a fuel-air mixture as a supplying unit for supplying fuel and air to the inside of the body 120, a metal ball 150 included on the surface of the electrode 130, and a secondary air supplying unit 160 for preventing reverse-current of the fuel-air mixture.

The burner 100 includes most constituent elements inside the outer casing 110 not to form a part extruding to the exhaust pipe outer side except a conducting bar 125 for applying voltage to the fuel-air mixture supplying unit 142, the secondary air supplying unit 160 and the electrode 130. At this time, the outer casing 110 is formed to have a hollow inside to be a specific portion of the exhaust pipe and includes a fixing unit 111 for connection with exhaust pipes of both sides at both end units.

That is, the outer casing 110 includes a constituent element such as the body 120 to form a specific portion of the exhaust pipe. Accordingly, exhaust gas flows by fixing the outer casing 110 to the exhaust pipe through the fixing unit 111 of the outer casing 110. The burner 100 of the present invention has a benefit that it can be easily installed on the exhaust pipe by using the fixing unit 111 by removing the exhaust pipe as large as the space that the burner 100 occupies without additional processes of inserting and fixing the constituent elements such as the body 120 formed inside the exhaust pipe.

The body 120 includes a reaction unit 121, an electrode supporting unit 122, the conducting bar 125 and the electrode 130 as portions that form a space where a flame is formed in the hollow inside and that are formed inside the outer casing 110.

One end unit of the body 120 is formed vertically to the moving direction of the exhaust gas to form the electrode supporting unit 122 for supporting the electrode 130. The body 120 is formed in a center of the outer casing 110 such that an exhaust gas flowing unit 112 where exhaust gas flows is formed between the body 120 and the outer casing 110. The body 120 may be supported by an additional supporting unit, the conducting bar 125 or the fuel-air mixture supplying unit 142 to be described below. The body 120 includes the reaction unit 121 that has a hollow inside and where flame ignited by a fuel-air mixture is formed. The inside of the body 120, i.e., the reaction unit 121, may have any shapes that can form flame but the body 120 has a cylindrical shape in this embodiment.

In the burner 100 of the present invention, the exhaust gas generated from the engine 200 enters the outer casing 110, passes through the exhaust gas flowing unit 112 between the body 120 and the outer casing 110, and moves to an exhaust gas passage 300 connected the Diesel particulate filter 400. Since one side of the body 120 has a center which is formed to be extruded toward an upper steam of the exhaust gas, it is preferred that as shown in FIG. 6, the exhaust gas, i.e., arrows, that entered the one side of the outer casing 110 is guided toward the exhaust gas flowing unit 112 along with one side of the body 120

One side of the body 120 may have a center of a protrusive shape. The center may have any shape, e.g., a conical shape, that the flow of the exhaust gas can be guided to the exhaust gas flowing unit 112 between the body 120 and the outer casing 110, without limitation.

The electrode supporting unit 122 supports the electrode 130 and fixes the conducting bar 125 for applying the voltage to the electrode 130. The electrode supporting unit 122 is formed on the upper stream of the exhaust gas of the body 120 and the direction of the flame by the electrode 130 is the same as that of the exhaust gas. When the electrode supporting unit 122 is formed on the opposite side, i.e., a downstream of the exhaust gas, and the flow of the exhaust gas is formed oppositely to the flame of the electrode 130, the flow of the exhaust gas is not smooth and it is difficult to form the flame due to the exhaust gas, thereby to cause a difficulty in heating the exhaust gas. Accordingly, it is preferable that the burner 100 of the present invention is formed such that the flame direction of the electrode 130 is the same as the flow direction of the exhaust gas. The electrode supporting unit 122 is formed of an insulating material such as a ceramic to be insulated from the body 120 and the electrode 130.

The conducting bar 125 is screwed to the electrode 130 without an additional wiring, to thereby prevent that wires are down due to vibration and friction. It is preferred that the conducting bar 125 includes an electrode cover 126 for covering a circumference with a material such as a ceramic to be insulated from the body 120.

The electrode 130 is formed in a longitudinal direction inside the body 120. The electrode 130 is formed of steel but may be formed of any materials that have superior electric conductivity and strong heat-resisting property. One side of the electrode 130 is fixed to the electrode supporting unit 122 and connected to the conducting bar 125 to receive power from the conducting bar 125. Other side of the electrode 130 is formed to be exposed to the reaction unit 121. The cross-sectional area of the electrode 130 decreases along with the moving direction of the exhaust gas. When power is applied to the electrode 130, electricity is discharged in the body 120, which is the closest to the surface of the electrode 130. The electric discharge starts in a neck unit of the electrode 130 to move with a swirl shape. The neck unit of the electrode 130 has a diameter which is the thickest on the electrode 130 and is a place, which is the closest point between the circumference of the electrode 130 and the body 120.

The metal ball 150 is formed on the surface of the electrode 130 in order to accurately control the point where the electric discharge starts. To be specific, the metal ball 150 may be formed on the circumference of the neck unit of the electrode 130. Since it is not possible to accurately control the point where the electric discharge starts in the neck unit of the electrode 130 due to errors in manufacture, it is for leading the electric discharge in the metal ball 150 by having the metal ball 150 in any one of the circumference of the neck unit in the electrode 130. Also, since the metal ball 150 is located in a place closest to the body 120 on the surface of the electrode 130, electricity is stably and accurately discharged on the surface of the electrode 130 where the metal ball 150 is located. It is preferred that the metal ball 150 is located in a place close to the point where fuel is injected in the circumference of the neck unit in the electrode 130. It is because the closer place is more advantageous in that fuel is injected accurately to the point where the electricity is discharged. It is also because when fuel injection point is far from the electric discharge point, igniting performance is deteriorated. The metal ball 150 has a hemisphere shape. The metal ball 150 is formed of steel same as the material of the electrode 130 but may be formed of any material which has a superior electric conductivity and strong heat-resisting property. It is obvious that the metal ball 150 may have any shape that has an effect for leading the electric discharge, e.g., a circular or multi-angular cone as well as a hemisphere shape. It is preferred in the electrode 130 that the cross-sectional area decreases gradually to the moving direction of the exhaust gas, i.e., from the point where the metal ball 150 is included to the other side. That is, it is preferred that when the other side of the electrode 130 is cut in a longitudinal direction, a section has a parabolic shape. Accordingly, the electric discharge that starts in the metal ball 150 moves with a swirl shape such as a spiral shape that starts in the metal ball 150 shown in FIG. 6.

With reference to FIGS. 4 to 5, the fuel-air mixture supplying unit 142 includes an air supplying unit 140, a rotational passage 143, an injecting unit 146 and a block 147. The air supplying unit 140 is formed on one side of the body 120 to supply air. The rotational passage 143 is connected to the fuel supplying unit 141 for supplying fuel and is formed on an inner wall of the body 120 as a means for supplying fuel and air to the inside of the reaction unit 121. The injecting unit 146 connects the rotational passage 143 and the reaction unit 121 to inject fuel and air. The block 147 is formed inside the rotational passage 143.

The fuel supplying unit 141 connects a fuel storage (not shown) and the outer side of the body 120 to supply fuel. The air supplying unit 140 is formed on the outer side of the body 120 and neighbors to the fuel supplying unit 141 to supply air.

The amount of fuel and air supplied from the fuel supplying unit 141 and the air supplying unit 140 is controlled through a control unit (not shown) and fuel mixed with air controlled by the control unit is supplied to the rotational passage 143 of the fuel-air mixture supplying unit 142. The air supplied through the air supplying unit 140 may be oxygen for oxidizing the fuel or air including the oxygen. The fuel mixed with the air supplied through the fuel supplying unit 141 and the air supplying unit 140 is vaporized by passing through the rotational passage 143 and discharged through the injecting unit 146.

The rotational passage 143 is a space though which a fuel-air mixture moves inside a wall forming the body 120. To be specific, the rotational passage 143 is formed between an inner wall and an outer wall of the body 120 along with a circumferential direction of the body 120. The fuel mixed with air is vaporized by passing through the wall of the body 120 heated through the exhaust gas mixed with air. Accordingly, ignition performance is improved in comparison with the case when fuel is supplied in a liquid state. Since the cross section of the body 120 has a circular shape, it is possible to inject the fuel mixed with air through the injecting unit 146 by generating turning force in the fuel.

When the fuel-air mixture moves to the injecting unit 146, the rotational passage 143 may be formed to lead the fuel-air mixture in a single direction. Since it takes a lot of time and costs to manufacture the rotational passage 143 inside the body 120 in one direction, a space, i.e., a groove, is formed by cutting the circumference of the body 120, and the rotational passage 143 is formed by covering and welding a body cover 145 of a ring shape. Since the rotational passage 143 formed by the above method is formed while drawing a circle inside the body 120, the fuel mixed with inflow air is bisected and transported to the injecting unit 146. In this case, the moving speed decreases and the fuel flows along with a comparatively fast path, there may be a section in which the fuel remains. It is possible in the above configuration to lead the fuel in a single direction by forming the block 147 in any one of from an inlet of the rotational passage 143 to the injecting unit 146 as shown in FIG. 5. Since maximizing the path of the rotational passage 143 is advantageous to vaporize the fuel mixed with air, it is preferred to lead the fuel-air mixture to another section which is formed to be comparatively long by minimizing a distance between the inlet and the injecting unit 146, and forming the block 147 in a near section.

The injecting unit 146 may be formed toward the metal ball 150 in order to inject the fuel vaporized toward the metal ball 150 where the electric discharge starts, to thereby improve ignition performance of the fuel supplied from the fuel-air mixture supplying unit 142.

With reference to FIGS. 3 to 6, the burner 100 of the present invention is connected to the outer side of the body 120 and additionally includes the secondary air supplying unit 160 for supplying air. The secondary air supplying unit 160 includes an outlet end 162 for inducing air from outside and injecting the air into the body 120. The secondary air supplying unit 160 plays a role of leading that the flame ignited in the metal ball 150 is formed in an exhaust gas flowing direction and also supplies oxygen required for ignition. The secondary air supplying unit 160 may be formed in the neck unit of the electrode 130, i.e., in a place between a point where the metal ball 150 is formed and the electrode supporting unit 122. Also, the outlet end 162 may be formed to be inclining at a selected angle in a vertical direction of the body 120 such that the induce air can move for the electrode 130. The air discharged through the outlet end 162 is shown as arrows in FIG. 6.

The vertical direction of the body 120 means a vertical direction to the flowing of the exhaust gas. Since the outlet end 162 is not to be formed in a central axis direction, but is formed to be inclining at a selected angle, the fuel and the air injected through the outlet end 162 flow while swirling around the electrode 130.

With reference to FIGS. 7 to 10, a second embodiment of the present invention will be described in detail while laying stress on a difference between the second embodiment and the first embodiment.

FIG. 7 is a perspective view showing a burner in accordance with the second embodiment of the present invention. FIGS. 8 and 9 cross-sectional views taken along the lines AA′ and BB′ in FIG. 7. FIG. 10 is a view showing an operating state of FIG. 7. FIG. 11 is a front view showing a magnifying pipe of the present invention.

As shown in FIG. 8, the body 120 is supported not by the conducting bar 125, but by an additional supporting unit.

The fuel supplying unit 141 and the air supplying unit 140 for supplying fuel and air are connected with the electrode supporting unit 122. A supplying unit for supplying fuel and air to the reaction unit 121 by being connected with the above constituent elements is formed on the center of the electrode supporting unit 122. The supplying unit is formed on a center of the electrode supporting unit 122 and includes a fuel passage 123 for passing fuel and an air passage 124 connected to the air supplying unit which covers a surface of the fuel passage 123. The fuel and the air are mixed in the end unit of the fuel passage 123 and the air passage 124 and supplied to the inside of the electrode 130 of the reaction unit 121.

Since the fuel passage 123 is formed in the central portion and the air passage 124 is formed to cover around the fuel passage 123, the fuel and the air are efficiently mixed and the fuel is atomized. Accordingly, combustion efficiency is improved. The air flowing inside the electrode 130 through the air passage 124 and the fuel flowing inside the electrode 130 through the fuel passage 123 become main materials to be reacted with the plasma.

As shown in FIG. 9, a plurality of nozzles 131 are formed on the upper part of the electrode 130 and the fuel mixed with air inside the electrode 130 moves outside the electrode 130 through the nozzle 131. The nozzle 131 is formed to be swirling at a selected angle with respect to a tangential direction of the electrode 130 such that the mixed fuel and air can rotationally flow while passing through the nozzle 131.

In addition, a voltage supplying unit for supplying voltage to the electrode 130 is extended from the outside of the outer casing 110 to be connected to the electrode 130 of the electrode supporting unit 122. The voltage supplying unit plays an additional role of fixing a location of the body 120 as well as a role of supplying voltage to the electrode 130.

Also, the burner 100 in accordance with the second embodiment of the present invention includes a secondary air passage 161 for supplying auxiliary air to the outside of the electrode 130 of the reaction unit 121, and further includes a secondary air supplying unit 160, which is extended from the outside of the outer casing 110 to supply auxiliary air to the secondary air passage 161.

The secondary air supplying unit improves combustion efficiency by being connected to the secondary air passage 161 such that the primarily mixed fuel and air are remixed with auxiliary air inside the electrode 130.

An outlet end 162 of the secondary air passage 161 for discharging auxiliary air to the outside of the electrode 130 may be formed to be inclining to the longitudinal direction of the body 120 in order to control flow of the auxiliary air such that the auxiliary air can rotationally flow the outside of the electrode 130.

The secondary air passage 161 is connected to the air passage 124 such that the amount of the air supplied to the inside of the electrode 130 can increase.

To have a look at the flow of fuel and air, the fuel supplied to the inside of the electrode 130 of the reaction unit 121 is supplied through the fuel passage 123 from the fuel supplying unit. The air supplied to the inside of the electrode 130 is supplied through the air passage 124 from the air supplying unit.

The auxiliary air supplied to the outside of the electrode 130 of the reaction unit 121 is supplied after passing the secondary air passage 161 through the secondary air supplying unit 160. The partial air enters the air passage 124. The mixed fuel, which is primarily mixed through the fuel passage 123 and the air passage 124 and supplied to the inside of the electrode 130 moves outside the electrode 130 through the nozzle 131 of the electrode 130 and secondarily mixed with the auxiliary air incoming through the secondary air passage 161.

The mixed fuel supplied by the nozzle 131 of the electrode 130 forms a flame in an entry direction of the exhaust gas by high-voltage current applied to the electrode 130. The flame heats the exhaust gas entering the outer casing 110 through the exhaust pipe.

The supplying unit of the burner 100 may include an electric heater 170. With reference to FIG. 4, the electric heater 170 is formed inside the fuel-air mixture supplying unit 142 and may adopt any method for receiving power and heating air and fuel flowing inside the fuel-air mixture supplying unit 142. The electric heater 170 may be formed on the upper stream of the fuel-air mixture supplying unit 142. The electric heater 170 plays a role of vaporizing fuel by heating the incoming air and fuel. The electric heater 170 is used when it is difficult to vaporize fuel by using the rotational passage 143 due to low temperature of the exhaust gas during start-up or at idle.

Accordingly, the electric heater 170 may adopt a Pulse Width Modulation (PWM) control method by detecting the temperature of the exhaust gas and controlling the operation based on the value of the detection temperature.

With reference to FIGS. 6, 10 and 11, a magnifying pipe 180 is formed at the end of the exhaust gas downstream of the body 120. When a cross section of the magnifying pipe 180 is getting closer to the end, a diameter of the cross section of the magnifying pipe 180 is lengthening longer than that of a cross section of the body 120. That is, the cross section of the magnifying pipe 180 may have a tapered shape. Since particulate matters (PM) included in the exhaust gas inside the reaction unit 121 are not trapped by preventing that the exhaust gas entering the inside of the outer casing 110 enters the inside of the body 120, i.e., the reaction unit 121. Accordingly, insulation effect is superior and malfunction of the burner 100 can be reduced.

In an inclined plane of the magnifying pipe 180, through holes 181 may be formed in a radial shape at regular distances centering around a central axis. Since the amount of oxygen supplied through the fuel-air mixture supplying unit 142 and the secondary air supplying unit 160 is insufficient as the amount of oxygen for ignition and combustion inside the reaction unit 121, it is required to induce some of the exhaust gas to the inside of the reaction unit 121 through the through hole 181. The flame generated through combustion inside the reaction unit 121 is combined with oxygen included inside the exhaust gas and formed more actively. Additionally, when oxygen is consumed through the through hole 181, it cause reduction of the exhaust gas.

It is possible to maximize combustion performance through the through hole 181 by forming one side of the magnifying pipe 180 in a front part on the body 120 in an incoming direction of the exhaust gas instead of the end of the electrode 130.

The terms and words used in the present specification and claims should not be construed to be limited to the common or dictionary meaning, because an inventor defines the concept of the terms appropriately to describe his/her invention as best he/she can. Therefore, they should be construed as a meaning and concept fit to the technological concept and scope of the present invention. Therefore, the embodiments and structure described in the present specification are nothing but one preferred embodiment of the present invention, and do not satisfy all of the technological concept and scope of the present invention. Therefore, it should be understood that many equivalents and modified embodiments that can substitute those described in this specification exist.

Advantageous Effects

According to a burner of the present invention, since flame of the burner is formed to be in parallel with exhaust gas, exhaust gas passing through an exhaust pipe is generally warmed up. Accordingly, a filtering performance of a Diesel particulate filter is consistently maintained and a life span of the Diesel particulate filter is improved.

Accordingly to the present invention, since the burner is formed to be a portion of the exhaust pipe, an additional space for having the burner is not required and durability can be improved.

The DPF regeneration burner of the present invention generates electric discharge in an electrode surface where a metal ball is located. The ignition performance of the burner is improved by accurately supplying a fuel-air mixture at a location where the electric discharge is generated.

Also, since fuel mixed with air is vaporized while passing through a passage of a rotation type existing inside a burner body heated by exhaust heat, ignition performance is improved in the fuel mixed with air in comparison with the fuel in a liquid state.

Ignition performance is improved by vaporizing fuel by using exhaust heat under the condition that the fuel is not sufficiently vaporized when an engine is cold or idles by primarily heating the fuel mixed with air by an electric heater and cooled before being transported to the inside of the burner body or when the engine idles.

DESCRIPTION OF DRAWINGS

The above and other objects, features and advantages of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:

FIG. 1 is a cross-sectional view showing a conventional plasma reactor.

FIG. 2 is a schematic view showing a Diesel particulate reduction device at which a burner of the present invention is installed.

FIG. 3 is a perspective view showing a burner in accordance with an embodiment of the present invention.

FIG. 4 is a cross-sectional view taken along the line AA′ in FIG. 3.

FIG. 5 is a cross-sectional view taken along the line BB′ in FIG. 3.

FIG. 6 is a view showing an operation state of FIG. 3.

FIG. 7 is a perspective view showing a burner in accordance with the second embodiment of the present invention.

FIG. 8 is a cross-sectional view taken along the line AA′ in FIG. 7.

FIG. 9 is a cross-sectional view taken along the line BB′ in FIG. 7.

FIG. 10 is a view showing an operating state of FIG. 7.

FIG. 11 is a front view showing a magnifying pipe of the present invention.

DETAILED DESCRIPTION OF MAIN ELEMENTS

100: burner 110: outer casing 111: fixing unit 112: exhaust gas flowing unit 120: body 121: reaction unit 122: electrode supporting unit 123: fuel passage 124: air passage 125: conducting bar 126: electrode cover 130: electrode 131: nozzle 140: air supplying unit 141: fuel supplying unit 142: fuel-air mixture supplying unit 143: rotational passage 145: body cover 146: injecting unit 147: block 150: metal ball 160: secondary air supplying unit 161: secondary air passage 162: outlet end 170: electric heater 180: magnifying pipe 181: through hole

BEST MODE

Hereinafter, the embodiments of the present invention will be described in detail with reference to accompanying drawings.

A burner for regenerating diesel particulate filter (DPF) which generates rotating electric discharge such as plasma or arc by applying high voltage to a reaction unit where there is rotation flow of fuel and air and generates ignition, includes: an outer casing which has a hollow inside to be a portion of an exhaust pipe for connecting a Diesel particulate filter for filtering particulate matters generated from an engine, and which includes a fixing unit 111 to be coupled with the exhaust pipe in both sides; a body which is formed inside the outer casing and includes a reaction unit; an electrode supporting unit which is formed inside the body; an electrode whose one side is fixed to the electrode supporting unit and which is installed on the reaction unit of the body; an electrode for supplying power to the electrode; a supplying unit for supplying fuel and air from the fuel supplying unit and the air supplying unit to the reaction unit; and an injecting unit which is formed to be connected to the supplying unit and injects fuel and air to the reaction unit.

The supplying unit may include a fuel-air mixture supplying unit for supplying a fuel-air mixture to the reaction unit by being connected to the air supplying unit and the fuel supplying unit, and the injecting unit injects the supplied fuel-air mixture to the reaction unit; and

a metal ball is included on a circumference of the electrode to initiate electric discharge at that point and ignite the injected fuel-air mixture.

The fuel-air mixture supplying unit may include a rotational passage between an inner wall and an outer wall of the body along with a circumferential direction of the body; and the injecting unit injects the fuel-air mixture passing through the rotational passage to the inside of the body.

A cross-sectional area of the electrode may decrease gradually along with the moving direction of the exhaust gas.

The burner, further includes: a secondary air supplying unit which is connected to an outer side of the body and which has an outlet end be connected to the reaction unit in order to supply air to the reaction unit,

wherein the secondary air supplying unit includes the outlet end, which is formed to be inclining at a selected angle with respect to the electrode, such that air supplied through the secondary air supplying unit flows in a moving direction of the exhaust gas by swirling along with a circumference of the electrode.

The burner may include an electric heater installed on the supplying unit,

wherein the electric heater is controlled by a Pulse Width Modulation (PWM) control method.

The body may include a magnifying pipe on a rear end, wherein the magnifying pipe includes a through hole and the magnifying pipe is located in a front position of the end of the electrode in an inflow direction of the exhaust gas.

MODE FOR INVENTION

A burner for regenerating diesel particulate filter (DPF) which generate rotating electric discharge such as plasma or arc by applying high voltage to a reaction unit where there is rotation flow of fuel and air and generates ignition, includes: an outer casing which has a hollow inside to be a portion of an exhaust pipe for connecting a Diesel particulate filter for filtering particulate matters generated from an engine with the engine, and which includes a fixing unit 111 to be coupled with the exhaust pipe in both sides; a body which is formed inside the outer casing and includes a reaction unit; an electrode supporting unit which is formed inside the body; an electrode whose one side is fixed to the electrode supporting unit and which is installed on the reaction unit of the body; an electrode for supplying power to the electrode; a supplying unit for supplying fuel and air from the fuel supplying unit and the air supplying unit to the reaction unit; and an injecting unit which is formed to be connected to the supplying unit and injects fuel and air to the reaction unit.

The supplying unit is formed on a center of the electrode supporting unit 122 and includes the fuel passage 123 connected to the fuel supplying unit and an air passage connected to the air supplying unit which covers a surface of the fuel passage 123, such that the fuel and the air are mixed in end units of the fuel passage and the air passage and are supplied to the reaction unit; and

since a plurality of nozzles are formed on an upper portion of the electrode, the mixed fuel and air moves outside the reaction unit along with the nozzle.

The nozzle may be formed to be inclining at a selected angle with respect to a tangential direction of the electrode such that the mixed fuel and air swirls.

The secondary air supplying unit including a secondary air passage, which includes the outlet end connected to the reaction unit such that auxiliary air flows outside the electrode of the reaction unit, supplies air to the secondary air passage,

wherein the secondary air supplying unit is formed to be inclining at a selected angle with respect to a longitudinal direction of the body such that air supplied by the secondary air supplying unit swirls.

The burner may include an electric heater installed on the supplying unit,

wherein the electric heater is controlled by a Pulse Width Modulation (PWM) control method.

The body may include a magnifying pipe on a rear end,

wherein the magnifying pipe includes a through hole and the magnifying pipe is located in a front position of the end of the electrode in an inflow direction of the exhaust gas.

The present application contains subject matter related to Korean Patent Application No. 10-2009-0054833, filed in the Korean Intellectual Property Office on Jun. 19, 2009, the entire contents of which is incorporated herein by reference.

Those skilled in the art will appreciate that the conceptions and specific embodiments disclosed in the foregoing description may be readily utilized as a basis for modifying or designing other embodiments for carrying out the same purposes of the present invention. Those skilled in the art will also appreciate that such equivalent embodiments do not depart from the spirit and scope of the invention as set forth in the appended claims.

INDUSTRIAL APPLICABILITY

A burner of the present invention relates to a force ignition burner for regenerating diesel particulate filter (DPF) and may be applied to a diesel particulate reduction device of a low-speed diesel vehicle. In addition, the burner may be used together with a burner using a passive regeneration method. The burner may be used in Diesel particulate reduction devices of diverse internal combustion engines which require force ignition due to insufficient heat of the exhaust gas although incomplete combustion of fuel occurs. 

1. A burner for regenerating diesel particulate filter (DPF) which generate rotating electric discharge such as plasma or arc by applying high voltage to a reaction unit where there is rotation flow of fuel and air and generates ignition, comprising: an outer casing 110 which has a hollow inside to be a portion of an exhaust pipe for connecting a Diesel particulate filter for filtering particulate matters generated from an engine, and which includes a fixing unit 111 to be coupled with the exhaust pipe in both sides; a body 120 which is formed inside the outer casing 110 and includes a reaction unit 121; an electrode supporting insulation unit 122 which is formed inside the body 120; an electrode 130 whose one side is fixed to the electrode supporting insulation unit 122 and which is installed on the reaction unit 121 of the body 120; a conducting bar 125 for supplying electric power to the electrode 130; a supplying unit for supplying fuel and air from the fuel supplying unit 141 and the air supplying unit 140 to the reaction unit 121; and an injecting unit 146 which is formed to be connected to the supplying unit and injects fuel and air to the reaction unit
 121. 2. The burner of claim 1, wherein the supplying unit includes a fuel-air mixture supplying unit 142 for supplying a fuel-air mixture to the reaction unit 121 by being connected to the air supplying unit 140 and the fuel supplying unit 141, and the injecting unit 146 injects the supplied fuel-air mixture to the reaction unit 121; and a metal ball 150 is included on a circumference of the electrode 130 to initiate electric discharge at that point and ignite the injected fuel-air mixture.
 3. The burner of claim 2, wherein the fuel-air mixture supplying unit 142 includes a rotational passage 143 between an inner wall and an outer wall of the body 120 along with a circumferential direction of the body 120; and the injecting unit 146 injects the fuel-air mixture passing through the rotational passage 143 to the inside of the body
 120. 4. The burner of claim 2, wherein a cross-sectional area of the electrode 130 decreases gradually along with the moving direction of the exhaust gas.
 5. The burner of claim 2, further comprising: a secondary air supplying unit 160 which is connected to an outer side of the body 120 and which has an outlet end 162 be connected to the reaction unit 121 in order to supply air to the reaction unit 121, wherein the secondary air supplying unit 160 includes the outlet end 162, which is formed to be inclining at a selected angle with respect to the electrode 130, such that air supplied through the secondary air supplying unit 160 flows in a moving direction of the exhaust gas by swirling along with a circumference of the electrode
 130. 6. The burner of claim 1, wherein the supplying unit is formed on a center of the electrode supporting unit 122 and includes the fuel passage 123 connected to the fuel supplying unit and an air passage connected to the air supplying unit which covers a surface of the fuel passage 123, such that the fuel and the air are mixed in end units of the fuel passage and the air passage and are supplied to the reaction unit 121; and since a plurality of nozzles 131 are formed on an upper portion of the electrode 130, the mixed fuel and air moves outside the reaction unit 121 along with the nozzle
 131. 7. The burner of claim 6, wherein the nozzle 131 is formed to be inclining at a selected angle with respect to a tangential direction of the electrode 130 such that the mixed fuel and air swirls.
 8. The burner of claim 7, wherein the secondary air supplying unit 160 including a secondary air passage 161, which includes the outlet end 162 connected to the reaction unit 121 such that auxiliary air flows outside the electrode 130 of the reaction unit 121, supplies air to the secondary air passage 161, wherein the secondary air supplying unit 160 is formed to be inclining at a selected angle with respect to a longitudinal direction of the body 120 such that air supplied by the secondary air supplying unit 160 swirls.
 9. The burner of claim 1, wherein the burner 100 includes an electric heater 170 installed on the supplying unit, wherein the electric heater 170 is controlled by a Pulse Width Modulation (PWM) control method.
 10. The burner of claim 9, wherein the body 120 includes a magnifying pipe 180 on a rear end, wherein the magnifying pipe 180 includes a through hole
 181. 11. The burner of claim 10, wherein the magnifying pipe 180 is located in a front position of the end of the electrode 130 in an inflow direction of the exhaust gas.
 12. The burner of claim 2, wherein the burner 100 includes an electric heater 170 installed on the supplying unit, wherein the electric heater 170 is controlled by a Pulse Width Modulation (PWM) control method.
 13. The burner of claim 3, wherein the burner 100 includes an electric heater 170 installed on the supplying unit, wherein the electric heater 170 is controlled by a Pulse Width Modulation (PWM) control method.
 14. The burner of claim 4, wherein the burner 100 includes an electric heater 170 installed on the supplying unit, wherein the electric heater 170 is controlled by a Pulse Width Modulation (PWM) control method.
 15. The burner of claim 5, wherein the burner 100 includes an electric heater 170 installed on the supplying unit, wherein the electric heater 170 is controlled by a Pulse Width Modulation (PWM) control method.
 16. The burner of claim 6, wherein the burner 100 includes an electric heater 170 installed on the supplying unit, wherein the electric heater 170 is controlled by a Pulse Width Modulation (PWM) control method.
 17. The burner of claim 7, wherein the burner 100 includes an electric heater 170 installed on the supplying unit, wherein the electric heater 170 is controlled by a Pulse Width Modulation (PWM) control method.
 18. The burner of claim 8, wherein the burner 100 includes an electric heater 170 installed on the supplying unit, wherein the electric heater 170 is controlled by a Pulse Width Modulation (PWM) control method. 